Class static members and static member functions

Static declared members or functions are shared by all objects of the class and do not save a copy in each class. They belong to the class itself, even if no object is instantiated, it can still be accessed or called. 650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>/* class static member */
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> # include <iostream>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> using namespace std;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src)" src = "http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif" align = "top"/> class {
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> static int a; // declare static members
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> int B;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> public:
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src = "http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif" align = "top"/> void set (int I, int j) {a = I; /* modify the value of static member a */B = j ;}
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> void show ();
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> };
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> int A: a; // definition section
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> void A: show ()
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> {
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> cout <" static member a: "<a <endl;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> cout <" non-static member B: "<B <endl;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>}
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> int main (int argc, char ** argv)
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> {
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> A aa1, aa2;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> aa1.set );
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> aa1.show ();
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src = "http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif" align = "top"/> cout <"++ + "<endl;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> aa2.set );
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> aa2.show ();
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src = "http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif" align = "top"/> cout <"++ + "<endl;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> aa1.show (); // any modifications to static member a can be reflected in other objects
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> return 0;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>} simply add a keyword static before the normal way of defining it to become a static member. However, it is worth noting how it is initialized because it is independent of class objects and cannot be initialized in constructors, because it should exist before all objects are instantiated (even if no constructor is called ). where is the initialization. In fact, you can find out where the class member functions are defined, much like declaring them externally. Note that there is no static. 650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src = "http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif" align = "top"/> int A: a; the declaration below is public and A value of 650 is initialized) this. width = 650; "onclick = 'window. open ("http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>/* class static member */
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> # include <iostream>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> using namespace std;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src)" src = "http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif" align = "top"/> class {
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> int B;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> public:
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> static int a; // declare static members
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src = "http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif" align = "top"/> void set (int I, int j) {a = I; /* modify the value of static member a */B = j ;}
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> void show ();
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> };
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> int A: a = 123; // definition section
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> void A: show ()
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> {
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> cout <" static member a: "<a <endl;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> cout <" non-static member B: "<B <endl;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>}
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> int main (int argc, char ** argv)
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> {
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> cout <A: a <endl;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> A aa1, aa2;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> aa1.set );
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> aa1.show ();
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src = "http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif" align = "top"/> cout <"++ + "<endl;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> aa2.set );
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> aa2.show ();
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src = "http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif" align = "top"/> cout <"++ + "<endl;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> aa1.show (); // any modifications to static member a can be reflected in other objects
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src = "http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif" align = "top"/> cout <"++ + "<endl;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> A: a = 100; // public can be accessed directly
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> aa1.show ();
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/> return 0;
650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'src =" http://www.bkjia.com/uploads/allimg/131228/1ZJM927-0.gif "align =" top "/>}
: 650) this. width = 650; "onclick = 'window. open (" http://blog.51cto.com/viewpic.php? Refimg = "+ this. src) 'alt =" "src =" http://www.bkjia.com/uploads/allimg/131228/1ZJL409-79.gif "border =" 0 "/>